• Insulin Dependent Diabetes (a.k.a. IDDM, Type I Diabetes)
  • Non-Insulin Dependent Diabetes (a.k.a. NIDDM, Type II Diabetes)
  • Insulin Dependent Type-II Diabetes
  • Gestational Diabetes

Hypoglycaemia (low blood sugar)

Causes of Hypoglycaemia:

  • Insufficient food intake after normal insulin taken
  • Insulin overdose
  • Heavy exercise without extra food or sugar
  • Nausea or vomiting after insulin or tablets (e.g. seasick diabetic)
  • Recent onset of infection
  • Excessive alcohol (usually on an empty stomach) resulting in reduced glucose output from liver
  • Diabetic Coma:
    • The two main causes of coma are:
      • Hypoglycaemia (rapid onset)
      • Hyperglycaemia (diabetic keto-acidosis; slow onset — hours or days)
    • Remember however, that diabetics can have coma from any other cause.

Information Needed:

  • Onset:
    • Sudden or gradual?
    • When was patient last well?
  • History:
    • Of current illness or stress, either emotional or physical.
    • Last meal.
    • Presence / absence of hunger or thirst.
  • Past history:
    • Diabetes mellitus.
    • Medic Alert tag.
    • Last insulin (time / amount).
    • Oral hypoglycaemic drugs.
    • Last food intake (related to insulin or tablets).

Signs and Symptoms:

  • Altered conscious state (mental status, confusion, inappropriate words or behaviour, often aggressive and / or obstructive to treatment)
  • Breath odour
  • Blood sugar level < 4.0mmol
  • Vital Signs and oxygen saturation
  • Skin; pale, cold, clammy, hydration
  • Sweating, tachycardia (bounding), fits, tremor, seizures
  • 'Medic Alert' or other medical information system?
  • Unconsciousness
  • Note: Chronic poorly controlled diabetes may be hypoglycaemic despite BGL >4. Signs of hypoglycaemia are masked by beta blockers.


  • The diabetic will frequently know what is needed — listen to the patient.
  • Hypoglycaemia can present as; seizures, coma, behaviour problems, intoxication, confusion, or stroke-like picture with focal deficits (particularly in elderly patients)
  • Patients who are elderly or who have been hypoglycaemic for prolonged periods of time may be slower to awaken. 

Hyperglycaemia (High Blood Sugar)

This condition has a gradual onset and usually develops over 12 — 48 hours. If uncorrected it leads to a variety of serious derangements in the body’s fluid and chemical balance, resulting in dehydration and eventually death. 

Causes of Hyperglycaemia:

  • Failure to take insulin or insufficient dosage.
  • Other disease, often an infection.

History frequently reveals:

  • Recent infection or illness
  • Gradual onset
  • Excessive urine output
  • Failure to monitor blood glucose levels adequately

Signs and Symptoms:

  • Gradual onset
  • Fruity breath odour
  • Kussmaul breathing (very deep and rapid)
  • Polyuria — frequent urination
  • Polydipsia — excessive thirst
  • Abdominal pain
  • Nausea / vomiting
  • Warm dry skin and sunken eyes
  • Dehydration
  • Weak, rapid pulse (tachycardia)
  • BGL usually >16
  • Drowsiness / coma / death

Page contributors:

DefaultDefault Author
St John WA
Want to help improve this article? Visit our Contribute page.

St John Ambulance Western Australia Ltd © Copyright 2020, All Rights Reserved

Privacy Policy | Copyright Statement & Disclaimer